Hello Dave, you wrote:

> What are the Aeolian Concertolas constructed out of?
> Brass plated steel?  Solid brass?  Gold plated brass or steel?

I can't hope to answer all your questions, however I had a look at some
of the changer parts of my piano Concertola and confirmed the following
which, up until now, I had assumed.

a. The circular side plates of the carousel look a lot like lacquered
brass and are not ferromagnetic.

b. The sides of the roll frame are similar in this regard.

c. The three rods that connect the sides of the roll frame together
(one being the centre shaft of the carousel) appear to be brass plated
steel as they match the other parts in colour but are ferromagnetic.

Hopes this helps a little bit.

Jim Heyworth
Sechelt, British Columbia, Canada